Abstract: The present invention relates to a process of preparing radiation sensitive silver halide grains containing at least 90 mole % silver iodide and having a morphological configuration of four hexagonal bipyramids each with bases joined to form a common tetrahedron. With this process, the hexagonal bipyramid portion of the grains can be elongated and/or truncated. In addition, the fraction of silver halide grains which have a configuration of four hexagonal bipyramids is increased.

Abstract: A process is disclosed of preparing a high chloride tabular grain emulsion for photographic use. An emulsion comprised of silver halide grains and a gelatino-peptizer dispersing medium in which morphologically unstable tabular grains having {111} major faces account for greater than 50 percent of total grain projected area and contain at least 50 mole percent chloride, based on silver, is formed in the presence of at least one 2-hydroaminoazine or xanthinoid morphological stabilizer adsorbed to surfaces of the tabular grains. Chemical sensitization of the emulsion and protonation of the morphological stabilizer are performed at least in part concurrently. Termination of protonation of the morphological stabilizer retains a portion of the morphological stabilizer on the surfaces of the chemically sensitized tabular grains.

Abstract: Photographic dye image transfer film units are disclosed employing negative working high aspect ratio tabular grain silver halide emulsions. The dye image transfer film units can achieve a variety of advantages, such as reductions in silver coverage with diminished reductions in speed, diminished increases in minimum density levels, allowing a transferred image to be rapidly accessible for viewing, and producing lower minimum densities and higher maximum densities for a given time of development, and greater image discrimination. Improvements in other photographic characteristics (such as sharpness), advantageous layer order arrangements, and reduction or elimination of various layers, such as yellow filter layers and scavenger interlayers can be obtained also.

Abstract: High aspect ratio chemically and spectrally sensitized tabular grain silver halide emulsions, photographic elements incorporating these emulsions, and processes for the use of the photographic elements are disclosed. In the tabular grain emulsions the silver halide grains having a thickness of less than 0.3 micron and a diameter of at least 0.6 micron have a high aspect ratio and account for at least 50 percent of the total projected area of the silver halide grains present.

Abstract: Radiographic elements are disclosed comprised of first and second imaging portions separated by an interposed support capable of transmitting radiation to which the second imaging portion is responsive. At least the first imaging portion includes a silver halide emulsion in which thin tabular silver halide grains of intermediate aspect ratios are present. Spectral sensitizing dye is adsorbed to the surface of the tabular grains. Crossover can be improved in relation to the imaging characteristics.

Abstract: A covering power, heat developable photographic material comprising, in binder, and in reactive association (a) negative-working photosensitive silver halide, (b) an image-forming combination comprising (i) an organic silver salt oxidizing agent containing a heterocyclic thione ligand or 1,2,4-mercaptotriazole ligand with (ii) an organic reducing agent and (c) a nucleating concentration of a hydrazino thiourea nucleating agent, enables a positive image to be developed and, in most cases, stabilized even though the photothermographic material contains no separate post-processing image stabilizer. The heat developable silver halide photographic material also enables development efficiency that is better than in those photothermographic silver halide materials not based on covering power imaging. A positive image can be developed in the heat developable photographic material after imagewise exposure by merely heating the material to moderately elevated temperatures.